The present invention is related to attachments for handheld dryer devices such as hair dryers and the like, and specifically to attachments for handheld dryers that pulse emitted air from the handheld dryers.
Handheld dryers such as hair dryers are generally known in the art. Typically they include a housing having an interior, a handle, and a barrel. An impeller is enclosed in the housing for forcing air at an increased velocity out of the barrel. A heater such as an electric coil is typically contained in the barrel for heating the air as it passes by. In operation, a user such as a hairstylist may direct the barrel in a desired direction to exploit the heated air flowing therethrough to dry the hair of a customer, for example.
Drying occurs as moisture is removed by the heated air. The speed at which a wet object such as hair may be dried generally depends on the capacity of the heated air to absorb moisture and the volumetric flow rate of the heated air contacting the wet object. For general purposes, the capacity of heated air to absorb moisture is determined by its relative humidity and its temperature. Although handheld dryers are generally known, problems and unresolved needs in the art remain. By way of example, non-uniform drying of the hair can occur, particularly near the roots. Further, the hair and the scalp can be overheated or dried out by a constant air current emitted from the hair dryer. Since the volumetric and velocity output of dryers are generally fixed depending on factors such as the impeller power and speed, the barrel configuration, air inlet size, and the like, the capability of the dryer to uniformly dry hair without overheating the hair and the scalp is generally limited.
Some attempts have been made to prevent overheating the hair and the scalp while attaining uniform dryness of the hair. To date, however, these attempts have met with only limited success. For example, some dryers are provided with impellers that are operable at different speeds to provide some variance in output. This disadvantageously adds cost and complexity to the dryer, however. Additionally, the dryer is limited to the impeller speed settings provided, which typically include only two or three speeds. Also, diffuser attachments are known for releasably fastening on the outlet of conventional dryers for diffusing airflow and/or for reducing the velocity of the flow. These attachments have not been useful, however, to provide variable frequency and volumetric output.
Also, many prior art diffusers and other attachments disadvantageously increase the back pressure on the dryer motor, thereby taxing the motor. For example, attachment of prior art diffusers to a dryer can cause the RPM of the motor to increase by 6% or more. This tends to lower the efficiency of the motor, to increase utility costs, and to shorten the service life of the dryer.
Air pulsing attachments are also known and are configured for time dependent deflections of the emitted air. Pulsing the air current gently and more uniformly dries hair from root to tip without overheating or drying out the hair or scalp. However, different hair types and scalps require different frequencies and volumetric output of pulse and, typically, the pulse frequency and volumetric pulse output of prior art air pulsing attachments are not variable, or are only variable as to the impeller speed.
Accordingly, these and other unresolved needs remain in the art.